1. Field of the Invention
The present invention relates to the field of heat exchangers, especially for motor-vehicle engine cooling installations. It relates more particularly to heat exchangers with flexible tubes, produced from plastic, for example.
2. Description of Related Art
Such heat exchangers, described especially in the unpublished French patent Application No 98 04966 by the Applicant, includes tubes produced from a substance which is substantially flexible and the extremities of which communicate with at least one manifold for a heat-exchange fluid, interacting, for example, with an airflow which passes through the exchanger.
So as to increase the thermal interaction by the flow with the tubes of the exchanger, it is currently desirable to maintain interstices between the tubes, through which the airflow penetrates. Such interstices should furthermore make it possible to perturb the flow in the manner of the perturbing vanes which heat exchangers with rigid tubes usually include.
The present invention then improves on the situation.
It is concerned with a heat exchanger having flexible tubes, of the abovementioned type, which, according to one general characteristic of the invention, includes means for holding the tubes in substantially parallel rows. The tubes are shaped so as to exhibit general shapes of substantially sinusoidal lines. The sinusoids of two tubes in contact, of two respective consecutive rows, are substantially mutually offset, with respect to one another, such that the two tubes are held in two contact areas per period of sinusoids.
The sinusoids of the respective tubes of two consecutive rows are preferably substantially in phase opposition, while the sinusoids of the same row are in phase.
According to another optional characteristic of the present invention, the contact areas of the respective tubes of consecutive rows are substantially inscribed within a plane perpendicular to the rows.
Advantageously, the spacing between the rows is substantially constant.
According to another advantageous characteristic of the invention, at least a part of the outer surface of the tubes, comprising the abovementioned contact areas, is coated with a layer of adhesive in order to form means for holding the tubes.
In one preferred embodiment of the present invention, the outer surfaces of the tubes carry a material made adhesive by a vulcanizing treatment, thus forming the abovementioned layer of adhesive.
In one more elaborate embodiment of the invention, the holding means further include a plurality of rods substantially perpendicular to the rows and each installed between the respective sinusoids of consecutive rows, in order to hold the tubes of the consecutive rows spaced substantially apart.